<template>
  <div class="star" :class="starType">
    <span v-for="(itemClass,index) in itemClasses" :class="itemClass" class="star-item" :key="index"></span>
  </div>
</template>
<script>
const CLS_ON = 'on'
const CLS_HALF = 'half'
const CLS_OFF = 'off'

export default {
  name: 'Star',
  props: {
    size: {
      type: Number,
      require: true
    },
    score: {
      type: Number,
      require: true
    },
    len: {
      type: Number,
      default: 5
    }
  },
  computed: {
    starType () {
      return 'star-' + this.size
    },
    itemClasses () {
      let result = []
      let score = Math.floor(this.score * 2) / 2
      let integer = Math.floor(score)
      let hasDecimal = score % 1 !== 0
      for (let i = 0; i < integer; i++) {
        result.push(CLS_ON)
      }
      if (hasDecimal) {
        result.push(CLS_HALF)
      }
      while (result.length < this.len) {
        result.push(CLS_OFF)
      }
      return result
    }
  }
}
</script>
<style lang="stylus" scoped>
@import "~styles/mixin.styl"
.star
  font-size 0
  .star-item
    display inline-block
    background-repeat no-repeat
  &.star-48
    .star-item
      width .4rem
      height .4rem
      margin-right .44rem
      background-size .4rem .4rem
      &:last-child
        margin-right 0
      &.on
        bg-image('img/star48_on')
      &.half
        bg-image('img/star48_half')
      &.off
        bg-image('img/star48_off')
  &.star-36
    .star-item
      width .3rem
      height .3rem
      margin-right .16rem
      background-size .3rem .3rem
      &:last-child
        margin-right 0
      &.on
        bg-image('img/star36_on')
      &.half
        bg-image('img/star36_half')
      &.off
        bg-image('img/star36_off')
  &.star-24
    .star-item
      width .2rem
      height .2rem
      margin-right .06rem
      background-size .2rem .2rem
      &:last-child
        margin-right 0
      &.on
        bg-image('img/star24_on')
      &.half
        bg-image('img/star24_half')
      &.off
        bg-image('img/star24_off')
</style>
